According to a comment, @Marco's answer to Notation about n choose k permutations was edited before migration. However, nothing displays in the edit history. (This seems appropriate to ask here since the original post, and the edit, happened on MO, but I have no objection to migrating to MMSE if that's more appropriate.)
When a thread is migrated from one site to another, only the latest revision of each post in the thread is moved over. To find the original revisions of a post on a migrated thread, you can do the following:
- Go to the timeline for the migrated post.
- Find the entry for the migration notice.
- Click on the link over the text "revisions" under the "comment" column.
However, unfortunately there is a bug due to which step 3 fails for migrated answers (but works fine for migrated questions). If you do click on the "revisions" link in this case, you'll find that it takes you to
https://mathoverflow.net/posts/431135/revisions. But, this is the revisions list of the question migrated from MathOverflow.
So, to find the revisions list of the answer, you need to find the post ID of the answer on MathOverflow, and use that in the above URL. To find the post ID of the answer, click on the link on "mathoverflow.net" in the same timeline entry, which takes you to
https://mathoverflow.net/questions/431135/notation-about-n-choose-k-permutations/431157?noredirect=1#431157. This points to the answer migrated from MathOverflow, and so its post ID is
So, the revisions history of this answer can be found at
- It is by design that only the latest revisions are moved over to the other site in a migration: see Does a migration remove edits from the edit history? on Meta SE.
- It is a known bug that the link to the revisions of a migrated answer points to the revisions of the migrated question: see Links to migrated answers' revision histories incorrectly go to the parent question's revision history instead of the answer's history on Meta SE.
- The link to the revisions list of a migrated post will always be accessible, even if the original post is later deleted: see Does the migration of edited posts violate attribution requirements? on Meta SE.